In the past, many different methods utilizing various different apparatus have been employed to effect the skewing of a stack of ferromagnetic laminations adapted for use in either a rotor or a stator of a dynamoelectric machine. In one of such past methods, the laminations of the stack were assembled on a mandrel for holding the stack, and at least one rather small passage adjacent the stack periphery was aligned so as to extend through the stack between a pair of opposite end faces thereof. When so assembled on the mandrel, one of the opposite end faces of the stack was seated on a base plate having an opening therein generally aligned with the mandrel, and during the seating of the stack, a skewing pin was inserted into the passage of the stack so as to be arranged at least adjacent or in abutment with the laminations of the stack within the passage therethrough. Of course, since the passage through the stack was rather small, as previously mentioned, the diameter of the skewing pin was necessarily also rather small. The skewing pin was pivotally mounted to the base plate and had a lower end extending therethrough adjacent a side of the base plate opposite that on which the stack was seated. In order to impart skew to the stack, a force was applied by suitable means onto the lower end of the skew pin beneath the base plate thereby to effect a preselected amount of pivoting or pivotal movement of the skewing pin about its pivotal mounting arrangement with the base plate. Of course, this pivoting movement of the skewing pin resulted in the skewing of the laminations of the stack through the engagement therewith of the skewing pin within the passage of the stack between the opposite end faces thereof. Subsequent to the above discussed skewing of the stack, a pressure pad was advanced into abutment with the other of the opposite end faces of the stack thereby to capture it between the pressure pad and the base plate in order to compress the stack which, of course, maintains the laminations of the stack in their skewed positions, and a tight pin previously associated with the mandrel was driven into displacement preventing engagement with the laminations of the stack while displacing the mandrel from the stack through the opening in the base plate. The pressure pad was retracted from its engagement with the stack, and the stack with the tight pin associated therewith was removed from the base plate and the skewing pin thereon. Of course, the tight pin retained the laminations of the stack in their skewed positions upon the removal of the stack and tight pin from the base plate. While the above discussed past method of imparting skew to the stack and the apparatus utilized therein may have had many salient features, it is believed that one of the disadvantageous or undesirable features thereof was that many of the skewing pins were broken due to the rather small size or diameter thereof particularly during the skewing of stacks of longer or greater stack heights. Of course, an ancillary disadvantageous or undesirable feature of the above discussed past method and apparatus is believed to be that the breakage of the skewing pins may have resulted in greater down time of such apparatus in order to replace such broken skewing pins which is also believed to have reduced production of such stacks. Further, another disadvantageous or undesirable feature of such above discussed past method and apparatus is believed to be that the proper amount of skew was not always imparted to the laminations of the stack since the skewing pins often deformed or were bent within their elastic limits during the skewing process when pivoted in response to the force applied thereon. In the event of the above discussed deformation of the skewing pins, it is believed that the angle of skew of at least some of the laminations at least adjacent the upper or other opposite end face of the stack may have been less than at least some of the other laminations adjacent the one opposite end face of the stack seated on the base plate of the skewing apparatus.
In some instances in the past, it is believed that a plurality of welds were laid across the stack while it was captured or otherwise compressed between the pressure pad and base plate, as discussed above, thereby to fixedly retain the laminations of the stack in their skewed positions; however, if such welds were applied, it is believed that the insertion of the tight pin into displacement preventive engagement with the laminations in order to maintain them in their skewed position may not have been necessary.